Bowen's disease of genital areas. An ultrastructural study.

Ultrastructural changes in specimens removed from Bowen's diseased genital areas of five patients are described, and a comparison is made with the tissue from the surrounding normal skin. Electron microscopic findings in Bowen's disease include an advanced dyskeratosis, acantholysis due to dissolution of desmosomal-tonofilament complexes, enlarged nuclei and nucleoli, increased polysome populations, mitochondrial alterations and nuclear inclusions. The basement membrane remains intact. Occasionally, atypical cells are undergoing cytolysis and are engulfed and phagocytized by the neighboring keratinocytes (apoptosis). The normal epithelium at the periphery of the lesion exhibits only a minimal degree of ultrastructural change.